LOR (re0 and user map) + PANIC

Marian Cerny jojo at matfyz.cz
Fri Sep 10 03:22:13 PDT 2004

Heh, I noticed one more LOR. This one happens when I turn the laptop off
using 'halt -p' after syncing disks. It's *hand*-rewritten, because the
laptop turned itself off after 10 seconds, despite the fact, that I was
inside kernel debugger (I took a shot with my digital photo camera).

lock order reversal
 1st 0xc177b6e8 re0 (network driver) @ /usr/src/sys/dev/re/if_re.c:1752
 2nd 0xc08adee4 user map (user map) @ /usr/src/sys/vm/vm_map.c:2997
KDB: stack backtrace:
kdb_backtrace(0,ffffffff,c08bde68,c08beb88,c084ddac) at kdb_backtrace+0x29
withness_checkorder(c08adee4,9,c0808137,bb5) at witness_checkorder+0x544
_sx_xlock(c08adee4,c0808137,bb5) at _sx_xlock+0x50
_vm_map_lock_read(c08adea0,c0808137,bb5,20000004,c16bae6c) at _vm_map_lock_read+0x37
vm_map_lookup(ceef9bb8,0,2,ceef9bbc,ceef9bac) at vm_map_lookup+0x28
vm_fault(c08adea0,0,2,8,c16b5b00) at vm_fault+0x66
trap_pfault(ceef9c80,0,c) at trap_pgault+0xf2
trap(18,10,10,0,3b) at trap+0x335
calltrap() at calltrap+0x5
--- trap 0xc, eip = 0xc0575b76, esp = 0xceef9cc0, ebp = 0xceef9cdc ---
re_rxeof(c177b000) at re_rxeof+0x2ae
re_intr(c177b000) at re_intr+0xb3
ithread_loop(c16bf400,ceef9d48,c16bf400,c05ed66c,0) at ithread_loop+0x124
fork_exit(c05ed66c,c16bf400,ceef9d48) at fork_exit+0xa4
fork_trampoline() at fork_trampoline+0x8
--- trap 0x1, eip = 0, esp = exceef9d7c, ebp = 0 ---

Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address   = 0xc
fault code              = supervisor write, page not present
instruction pointer     = 0x8:0xc0575b76
stack pointer           = 0x10:0xceef8cc0
frame pointer           = 0x10:0xceef9cdc
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, def32 1, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 22 (irq11: re0 ohci0+)
[thread 100019]
Stopped at      re_rxeof+0x2ae: movl    %eax,0xc(%edi)

This LOR might be obsolete, because I'm not using patched version of
if_re0.c for the LOR #26 in LORs database (I'm using 5.3-BETA3). After
5.3-BETA4 will be available, I can send, wether this patch helped in
this situation also, because I get this LOR + PANIC in 30% of shutdown

Marian Cerny

Marian Cerny <jojo at matfyz.cz>
Jabber: jojo at njs.netlab.cz

[ UNIX is user friendly. It's just selective about who its friends are. ]

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